Just a heads up to let you all know that we have now enabled a "Similar Thread Search" function for vBulletin.
A quick low down on what it does:
Automatic Similar Thread Search
This option will cause a search for similar threads to be automatically done when a new thread is posted. These similar threads are then linked to from the newly posted thread's page.
We will be monitoring how this automatic search will affect forum performance and the option and its results will improve over time as it indexes previous posts.